The present invention relates to a system for assisting with the regeneration of a particulates filter incorporated into the exhaust line of an engine, particularly of a motor vehicle.
It is known that one of the most outstanding concerns of equipment manufacturers and motor vehicle manufacturers is that of reducing the pollution caused by the operation of their engines.
This is particularly true of diesel engines.
Various solutions have therefore been envisaged in an attempt at reducing the level of pollution of these engines.
Thus, for example, it has already been proposed in the state of the art that particulates filters be incorporated into the exhaust lines of these diesel engines.
These filters are therefore designed to trap the particulates or soot contained in the exhaust gases of these engines and to burn them during a filter regeneration phase.
Various means for assisting with the regeneration of these filters have already been developed in the prior art.
Now it is known that the natural regeneration temperature for soot is at around about 550 to 600xc2x0 C.
Now, these temperatures can be achieved only when these engines are running under very high load conditions.
To make regeneration easier at light load, these particulates filters may be combined with oxidation catalytic converters arranged upstream of them.
The prior art has also developed other systems for assisting with the regeneration of these filters and which comprise means of injecting fuel into the cylinders of the engine while these are on their expansion stroke, in order to raise the temperature of the exhaust gases so as to assist with regenerating the filter.
The development of these systems is associated with the emergence of systems for the common supply of fuel to the cylinders of the engines, also known as common rail injection systems.
However, these systems do display a certain number of drawbacks, particularly as far as the impact that this post-injection has on the engine torque supplied.
What happens is that such post-injection results in relatively significant fluctuations in engine torque, and this has a corresponding detrimental effect on the driveability of the vehicle.
The object of the invention is therefore to solve these problems.
To this end, the subject of the invention is a system for assisting with the regeneration of a particulates filter incorporated into an exhaust line of an engine, particularly of a motor vehicle, of the type comprising means of injecting fuel into at least some of the cylinders of the engine while these are on their expansion stroke, in order to raise the temperature of the exhaust gases therein so as to assist with regenerating the filter, characterized in that the injection means are designed to inject a number of shots of fuel, in metered amounts distributed over time during the expansion stroke, in that the engine is associated with a turbocompressor and in that the system comprises means for regulating the boost pressure of the turbocompressor so as to reduce the amount of air entering the engine.
The invention will be better understood from reading the description which will follow, given merely by way of example and made with reference to the appended drawings, in which: